Example 2: One parent has identical pairs and the other parent has the identical pairs of genes but the genes are different from each other.

Circle circle

Circle circle

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Square square

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Square square

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One parent has identical pair of genes

So does the other parent—but the 2 parents are different from each other.

Results: All the offspring has the same combination of genes, which is circle-square

Example 3: Circle

Square

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Circle

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Square

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One parent has circle—square pairs

One parent has circle—square pairs

Circle—square are passed to offspring

All offspring has circle—square pairs

Both parents are the same—they each have different pair of genes—circle-square combinations. Each parent can pass on either square or circle genes. The offspring can have 3 different types of genes pairs possible. The types of combinations that can result will follow the mathematical laws of chances.

Note: Mixed pairs of genes will result in the dominant gene dictating the feature that will result.

EXERCISE 4:

1. Get two hundred index cards

2. Draw circles on 100 cards and squares on the other 100 cards

3. Put 100 squares and 100 circle cards in each container

4. Mix well.

5. Draw card from each container and pair them

6. Repeat until all cards are used

7. Chart the results

What proportions were square-square, circle-circle, and square-circle pairs?